Field of the Invention
This invention relates generally to devices for reconstitution of a first fluid with a second fluid and more particularly to a pressure equalizing device for attachment between a fluid container and a receptacle for equalizing pressure within the container and receptacle.
Background of the Related Art
Certain drugs or medicaments (those terms being used interchangeably herein) are preferably provided in powder or dry form (such as a lyophilized form), and require reconstitution prior to administration. Lyophilized drugs, for example, typically are supplied in a freeze-dried form that needs to be mixed with a diluent to reconstitute the substance into a form that is suitable for injection. Medicaments may also be provided in other dry or powder forms that require reconstitution.
In addition, drugs may be provided as multi-part systems which require mixing prior to administration. For example, one or more liquid (e.g., flowable (slurry or liquid)) components, and/or dry (e.g., powdered or granular) components may be provided in a drug container or delivery device which require mixing prior to administration. Gondatropin and interferon are examples of such multi-component substances which are typically mixed just prior to being administered to a patient.
Drug reconstitution generally involves transferring a solvent from one container to a sealed vial containing the drug in powder or liquid form, by means of a needle, syringe, or transfer set. In some circumstances, the reconstituted fluid may be inadvertently released into the atmosphere in gas form or by way of aerosolization, during the withdrawal of the needle from the vial and while the needle is inside the vial if any pressure differential between the interior of the vial and surrounding atmosphere exists.
Certain drugs, medicaments, and drug systems may become toxic when reconstituted creating a risk of contamination for practitioners, pharmaceutical personnel, and patients. When preparing and administering such toxic substances, care must be taken to avoid contamination. Safety boxes, cabinets, or isolators are often used to prepare drugs to reduce the risk that toxic substances will leak to the surrounding environment. However, such facilities are non-portable and, generally, require substantial space in a clinical setting. Such facilities are also expensive to install, maintain, and repair.
Alternatively, a closed pressure equalizing device may be attached between the vial and fluid container during reconstitution to reduce the risk that the reconstituted fluid will be inadvertently released. The pressure equalizing device comprises a gas container in communication with the interior of the vial, which ensures that neither an increased pressure nor a vacuum can occur inside the vial when gas or liquid is injected into or withdrawn from the vial. The gas container may be filled with cleaned or sterilized air prior to its use to ensure that the contents of the vial do not become contaminated with air-borne particles such as dust, pollen, mould, or bacteria and other undesirable substances. A closed pressure equalizing system for use in drug reconstitution is disclosed in U.S. Pat. No. 8,029,747, entitled “Pressure Equalizing Device, Receptacle and Method”, the disclosure of which is incorporated herein by reference in its entirety.
A further pressure equalizing device is disclosed in U.S. Pat. No. 7,900,659, entitled “Pressure Equalizing Device for Vial Access” (hereinafter “the '659 patent”). The '659 patent discloses a vial access device having a pressure equalizing chamber delimited by a slideable disk. The disk automatically moves within the chamber to maintain the vial at atmospheric pressure during reconstitution and aspiration of the vial's contents. The device further includes a hydrophobic filter disposed in a port between the vial and pressure equalizing device for preventing fluid from entering the pressure equalizing chamber.
A disadvantage with such a pressure equalizing vial access device is that the filter may become clogged with solid particles, such as powder, carried agglomerates, or high viscose liquid from the fluid transferred between the pressure equalizing vial access device and the vial. The solid particles may hinder or prevent pressure equalization. The pressure equalizing vial access device also takes up valuable space around the vial opening since the longitudinal axis of the pressure equalizing chamber is arranged at a 90 degree angle relative to the longitudinal axis of the vial. Accordingly, it may be difficult to use the pressure equalization device in locations having limited space such as hospital rooms, laboratories, and other clinical settings. Furthermore, a vial having such a pressure equalizing vial access device attached is generally top-heavy and may topple over if the pressure equalizing vial access device is not supported by a user. The pressure equalizing device of the present invention is provided to address the above identified deficiencies.